IntroductionSoil amendments aim to improve soil properties. This includesincrease of the soil organic matter and of the nutrient pool,stimulation of beneficial microbial populations and/or suppressionof pathogens and weeds. The desired outcome of all these benefi-cial effects is the improvement of soil fertility and consequently ofits productivity. Soil amendments are of particular importance inorganic farming; most often, they are composted organic materialsof different origin.